Electric incandescent lamp and holder thereof



E. R. GROTE Jan. 24, 1933.

ELECTRIC INCANDESCENT LAMP AND HOLDER THEREOF Filed Sept. 18. 1950 Patented Jan. 24, 1933 PATENT" OFFICE EDWIN RUDOLPH GBOTE, OF WIMBLEDON, LONDON, ENGLAND ELECTRIC INCANDESCENTLAMP AND HOLDER THEREOF Application filed September 18, 1930, Serial No.

This invention relates to electric incandescent lamps of the kind in which a filament is extended longitudinally ofan elongated tubular body well into the substantially hemi-spherical endsthereof, the lamp caps being disposed laterally of the body, so that the filaments of adjacent lamps may be brought more closely together when the lamps are arranged in line within a channel or like shaped reflector or lamp holder.

The object of the present invention is to provide an improved construction of such lamps and of holders therefor.

According to this invention the lateral lamp caps are so formedthat'they may be engaged with contact devices arranged in the lamp holder to holdjthe lamps in the correct position and prevent accidental falling out thereof. I v f.

For example the holder may be provided with contact sockets or their equivalent adapted to receive the lamp caps and means such as spring clips or locking members may be provided to retain the lamp caps in the sockets or the like, the caps being suitably shaped to permit of a positive engagement with the locking members and sockets.

Means may be provided whereby the grip on the contacts is first released before the lamp is withdrawn.

Provision is also made in the contact devices to allow for longitudinal expansion of the lamp bodies.

One construction of the improved lamp and holder will now be more particularly described with reference to the accompanying drawing, wherein Fig. 1 is a front elevation of a portion of a holder showing two lamps secured in the operative position. therein.

Fig. 2 is a transverse section thereof, drawn to a larger scale, partly in elevation.

Fig. 3 is a longitudinal section of the holder, taken on the line 3-3 of Fig. 2, showing some parts broken away, and

Fig. 4 is a fragmentary transverse section taken on the'line 4t4.- of Fig. 3.

Fig. 5 is a diagrammatic drawing, showing the circuit employed.

As .shown in Figs. 1 and 2, each of the 482,886, and in Great Britain October 9, 1929.

tending glassor other suitable rod or tube v 5 suitably supported within the tubular body 1.

The wires conducting current to'the filament are led out of the lamp to lateral lamp caps or bases 6 suitably secured on the seal points 7 through which the said wires pass.

As the lamps are especially intended for concealed lighting purposes they are ar-.

ranged in line within a reflector 8 of sub-' stantially channel section. As will be seen from F igs." 2 to a this reflector is formed with a longitudinally extending channel section depression 9 within which are accommodated the contact devices adapted to engage the lamp caps 6 for the purpose of supplying current thereto and securing them in the reflece tor 8.- I

Each contact device, as shownmore clearly in Fig. 3, comprises an elongated rectangular block. 10 of insulating material formed adjacent one end with an elongated recess 11 and adjacent the other end with a circular recess 12.. F

The dimensions of the recess 12 are such that alamp cap 6 may be inserted therein easily with ajlittle play while, in the case of the recess .11, the dimensions are such thata lamp cap 6 be inserted therein with but slight play transversely of the reflector 8 and with a larger though limited amount of play longitudinally of the reflector.

. This longitudinal play-allows for expan sion taking place in the lamp bodies, as will belunderstood, the contact devices being suitably spaced apart in the channel 9 so that one lamp cap of each lamp is engaged in a recess and the other lamp cap is engaged in a recess'll (see Fig. 1). i y

In order that the lamp caps may be securelyheld in the socket recesses 11 and 12, the block 10 of insulating material is recessed longitudinally in itsupper or outer surface, as shown at 13, to receive a wire spring catch member 14 adapted to extend across' the openings to the recesses 11 and 12 and engage resiliently with a circumferential groove 15 formed in the lamp cap 6. The

end 16 of the lamp cap is preferably of conical formation to facilitate the insertion of the cap into the recess 11 or 12, the conical surface 16 forcingthe spring member 14 out of the path of the cap during this operation. i

The spring member 14 is accommodated near its centre in the groove 17 in the upper surface of a cylindrical contact stud, 18 to the underside of which one of the current conducting leads 19 is connected by means of a binding screw 20. These leads 19 'are dis-' posed longitudinally in thebottom of the channel 9 being accommodated in grooves 21 formed on the edges of the blocks at the points where the latter are arranged in the channel 9. H v

A metal plate 22 is secured by means of a screw 23 (Fig. 3) in a recess in the block 10, to cover the spring member 14, being in electrical contact with the stud 18v and formed Figs. 2'and-4) and an insulating strip 27 is disposed between the inner surface of said member 26 and the plate 22 to insulate these parts from one another. This insulating strip 27 is preferably secured to the member 26 so that removal of the latter from thereflector 8 exposes the contact devices for purposes of inspection or repair. It will be understood that the channel section member 26 and the insulating strip 27 are suitably with apertures 24 and 25 corresponding in.

Any longitudinal ex ansion of the lamp body which may occur uring the use thereof is accommodated by the automatic displacement of that lamp cap which is engaged in the elongated recess 11 of the block 10.

I claim 1. A reflector for use with elo ated, tubular electric lamps having latera contacts adjacent each end, the reflector being formed to provide a longitudinally extending channel inits' bottomadapted' to receive sockets and having outwardly flaring reflecting surfaceson eaohside'of the channel, and a plate detachably enga ed with the channel and extending over tlie channel and forming a continuation of the outwardly flaring reflecting surfaces, said plate being apertured for the passage of lamp bases.

2.1K reflector for elon ated, tubular electric lam s havi latera contacts adjacent each en the re cto'r comprisingaqlongitudinally extendin channel portion and outwardly flaring re acting portionson each sideof the channel portion, the, walls of the channel portion adjacent the reflecting portions being outwardly. offset, and a plate flanged at its margins, the flanges hei adapted to beinserted in the outwardly o 1 set portions of the channel, the, face of the plate beingapproximately flush with the ad acent margins ofthe reflecting portions, the

plate havingapertures for the reception of signature.

EDWIN RUDOLPH GROTE.

aperturedwhere they register with the re- 7 cesses 11 and 12; 7

d The spring catch member 14 preferably bears on the shank of the screw 23, as well as on the wall of the groove 17 in the contact stud 18, so that the terminal portions of.

the spring member 14 aresupported sufliciently firmly while being resiliently displaceable when lamp caps are inserted in the openings 24, 25 of the-metal contact plate 22.v

As shown in Fig. 3 the ends of the spring member 14 are preferably bent substantial-1y at. right-angles to bear against. the wall of reflector is but a simple operation, while the" spring catch members preventaccidental displacement of the lamps fromthe holder due to their'positive engagement with the lamp 5 caps. v

the recess 13 in the block 10 and'mainta'inthe: correct positions. of those portions of the extend acrossthe openings 24 

